W DOC AIRBUS | TSM A320F

Loss of the Visual Warning for Mode 5 (Glide Slope)

TASK 34-48-00-810-815-A
Loss of the Visual Warning for Mode 5 (Glide Slope)

1. Possible Causes
  • wiring of the F/O GPWS/G/S pushbutton switch (4WZ)
  • wiring of the annunciator light test and interface board (4LP)
  • P/BSW-GPWS/G/S [5WZ]
  • wiring of the CAPT GPWS/G/S pushbutton switch (5WZ)
  • P/BSW-GPWS/G/S [4WZ]
  • GPWC [1WZ]
  • BOARD-ANN LT TEST & INTFC [4LP]
  • C/B-EIS/GPWS/28VDC [2WZ]
  • wiring of the F/O PULL UP/GPWS pushbutton switch (4WZ)
  • wiring of the CAPT PULL UP/GPWS pushbutton switch (5WZ)
2. Job Set-up Information
 A. Referenced Information
REFERENCE
DESIGNATION
ESPM 2045110
AMM 33-14-33-000-001
Removal of the Annunciator-Light Test and Interface-Board
AMM 33-14-33-400-001
Installation of the Annunciator-Light Test and Interface-Board
AMM 34-48-00-710-001
Operational Test of GPWS Ground Self-test Function
ASM 344801
AMM 34-48-34-000-001
Removal of the GPWC
AMM 34-48-34-400-001
Installation of the GPWC
3. Fault Confirmation
Subtask 34-48-00-710-054-D ** ON A/C NOT FOR ALL
A. Test
   (1) Do the operational test of Enhanced GPWS ground self-test function AMM 34-48-00-710-001.
   (2) Make sure that the G/S legend of the CAPT and F/O GPWS/G/S pushbutton switches comes on.
Subtask 34-48-00-710-054-F ** ON A/C NOT FOR ALL
A. Test
   (1) Do the operational test of Enhanced GPWS ground self-test function AMM 34-48-00-710-001.
   (2) Make sure that the GPWS legend of the CAPT and F/O PULL UP/GPWS pushbutton switches comes on.
4. Fault Isolation
Subtask 34-48-00-810-067-A ** ON A/C NOT FOR ALL
A. If the G/S legend of one or two GPWS/G/S pushbutton switches does not come on:
  • on the panel 25VU, set the INT LT/ANN LT switch to TEST and do a check to see if the G/S legends come on.
   (1) If the two G/S legends do not come on:
  • do a check of the wiring of the F/O GPWS/G/S pushbutton switch (4WZ):
    . pin A/8 to the first terminal block
    . pin A/9 to pin A/5
    ASM 344801.
     (a) If there is no continuity:
  • repair the above wiring.
     (b) If there is continuity:
  • do a check and repair the wiring of the annunciator light test and interface board (4LP) from pin A/37 to the first terminal block ASM 344801.
   (2) If the G/S legend of the CAPT GPWS/G/S pushbutton switch only does not come on:
     (a) If the fault continues:
  • do a check and repair the wiring of the CAPT GPWS/G/S pushbutton switch (5WZ) :
    . pin A/4 to the first terminal block
    . pin A/9 to pin A/5
    . pin A/8 to F/O GPWS/G/S pushbutton switch (4WZ) pin A/6
    ASM 344801.
   (3) If the G/S legend of the F/O GPWS/G/S pushbutton switch only does not come on:
     (a) If the fault continues:
  • do a check and repair the wiring of the F/O GPWS/G/S pushbutton switch (4WZ) from pin A/4 to the first terminal block ASM 344801.
   (4) If the two G/S legends come on:
     (a) If the fault continues:
       1 If the fault continues:
  • do a check of the wiring of the annunciator light test and interface board (4LP):
    . pin A/38 to GPWC (1WZ) pin AB/3D
    . pin A/40 to pin A/20
    . pin A/21 to the circuit breaker 2WZ
    ASM 344801.
         a If there is no continuity:
  • repair the above wiring.
         b If there is continuity:
  • replace the C/B-EIS/GPWS/28VDC [2WZ] .
Subtask 34-48-00-810-067-C ** ON A/C NOT FOR ALL
A. If the GPWS legend of one or two PULL UP/GPWS pushbutton switches does not come on:
  • on the panel 25VU, set the INT LT/ANN LT switch to TEST and do a check to see if the GPWS legends come on.
   (1) If the two GPWS legends do not come on:
  • do a check of the wiring of the F/O PULL UP/GPWS pushbutton switch (4WZ):
    . pin A/8 to the first terminal block
    . pin A/9 to pin A/5
    ASM 344801.
     (a) If there is no continuity:
  • repair the above wiring.
     (b) If there is continuity:
  • do a check and repair the wiring of the annunciator light test and interface board (4LP) from pin A/37 to the first terminal block ASM 344801.
   (2) If the GPWS legend of the CAPT PULL UP/GPWS pushbutton switch only does not come on:
     (a) If the fault continues:
  • do a check and repair the wiring of the CAPT PULL UP/GPWS pushbutton switch (5WZ) :
    . pin A/4 to the first terminal block
    . pin A/9 to pin A/5
    . pin A/8 to F/O PULL UP/GPWS pushbutton switch (4WZ) pin A/6
    ASM 344801.
   (3) If the GPWS legend of the F/O PULL UP/GPWS pushbutton switch only does not come on:
     (a) If the fault continues:
  • do a check and repair the wiring of the F/O PULL UP/GPWS pushbutton switch (4WZ) from pin A/4 to the first terminal block ASM 344801.
   (4) If the two GPWS legends come on:
     (a) If the fault continues:
       1 If the fault continues:
  • do a check of the wiring of the annunciator light test and interface board (4LP):
    . pin A/38 to GPWC (1WZ) pin AB/3D
    . pin A/40 to pin A/20
    . pin A/21 to the circuit breaker 2WZ
    ASM 344801.
         a If there is no continuity:
  • repair the above wiring.
         b If there is continuity:
  • replace the C/B-EIS/GPWS/28VDC [2WZ] .
Subtask 34-48-00-710-055-A
B. Do the test given in Para. 3.
5. Close-up
Subtask 34-48-00-860-051-A
A. Put the aircraft back to its initial configuration.
   (1) On the panel 25VU, set the INT LT/ANN LT switch to BRT.
[Rev.8 from Aug 2018] 2026.04.04 04:33:15 UTC
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